THE SOLUBILITY IN WATER OF CERTAIN NATURAL SILICATES. 
By George Steiger. 
The results cited in the preceding paper are purely qualitative in 
character. The following experiments are analogous in kind, but are 
aimed at putting the subject on a quantitative basis. In both investi- 
gations the same samples of material were employed, so that the data 
are fairly comparable. 
The work was carried out as follows: One-half gram of each of the 
finely ground minerals was weighed out, and placed in a 2-ounce 
bottle with 50 cubic centimeters of water. These bottles were set aside 
where the temperature remained about 70° F. for one month, and were 
skaken from time to time. At the end of the period all were filtered, 
and the solutions were titrated with a standard hydrochloric acid 
solution, methyl orange being used for an indicator. 
What has gone into solution by this treatment I can not say — some- 
times soda, sometimes potash, possibly sometimes lime, but for the 
-sake of comparison the results in the following table have been calcu- 
lated in terms of Na 2 Oj although the percentage of sodium is very 
small in some of the specimens. I have given also in another column 
the x>ercentage of the combined alkalies as shown by analysis of speci- 
mens from the same localities. 
Pectolite, Bergen Hill, N. J .. 
Muscovite 
Natrolite, New Jersey 
Lintonite, Lake Superior 
Phlogopite, Edwards, N. Y.. . 
Laumouite 
Lepidolite, Maine 
Formula. 
ELeohte, Litchfield, Me ... 
Heulandite, Nova Scotia . . 
Orthoclase KAlSi 3 0* 
Ca,(SiO :i ): $ NaH 
Al3(Si0 4 ) 3 KH 2 
Al,(Si0 4 )3Na 2 H 4 
AL(SiO. ! ) ( i(CaNa,) :i .7H:0 .. 
Al(Si0 4 ) 3 Mg 3 KH. 2 
Al,Si0 4 Si30 8 Ca.4H,0 
fKHLiAL(Si0.i) ;i 
lK 3 Li :5 (AlF 2 ) 3 Al(Si 3 8 ) 3 . ... 
Al 3 (Si0 4 )3Na 3 
Al 6 (Si 3 8 ) 6 (CaNa 2 ) 3 .16H 2 0. 
lVr rout of 
combined 
alkalies by 
analysis. 
9.11 
10.00 
15.79 
5. 92 
9. 32 
1.00 
13. 00 
21. 17 
2. 00 
16.00 
Equivalent 
Of Xa,<) in 
solution. 
0.57 
.32 
.30 
.29 
. 22 
.18 
. 18 
.16 
. 13 
.11 
159 
